Regulation of glycogen synthase

Identification of residues involved in regulation by the allosteric ligand glucose-6-P and by phosphorylation

Bartholomew A. Pederson, Christine Cheng, Wayne A. Wilson, Peter Roach

Research output: Contribution to journalArticle

54 Citations (Scopus)

Abstract

The major yeast glycogen synthase, Gsy2p, is inactivated by phosphorylation and activated by the allosteric ligand glucose-6-P. From studies of recombinant proteins, the control can be accommodated by a three-state model, in which unphosphorylated enzyme has intermediate activity (state II). Glucose-6-P increased V(max)/K(m) by about 2-fold (state III), whereas phosphorylation by the cyclin-dependent protein kinase Pcl10p/Pho85p decreased V(max)/K(m) by ~30-fold (state I). In the presence of glucose-6-P, state III is achieved regardless of phosphorylation state. The enzyme forms complexes in solution with the yeast glycogenin Glg2p, but this interaction appears not to affect control either by glucose-6-P binding or by phosphorylation. Scanning mutagenesis was applied to identify residues potentially involved in ligand binding. Of 22 mutant enzymes analyzed, seven were essentially inactive. Five mutant proteins were altered in their activation by glucose-6-P, and two were completely unaffected by the hexose phosphate. One of these, R586A/R588A/R591A (all three of the indicated Arg residues mutated to Ala), had wild-type activity and was normally inactivated by phosphorylation. A second mutant, R579A/R580A/R582A, had somewhat reduced V(max), but its activity was not greatly reduced by phosphorylation. The Arg residues in these two mutants are restricted to a highly conserved, 13-residue segment of Gsy2p that we propose to be important for glucose-6-P binding and/or the ability of the enzyme to undergo transitions between activity states.

Original languageEnglish
Pages (from-to)27753-27761
Number of pages9
JournalJournal of Biological Chemistry
Volume275
Issue number36
DOIs
StatePublished - Sep 8 2000

Fingerprint

Allosteric Regulation
Glycogen Synthase
Phosphorylation
Ligands
Glucose
Enzymes
Yeast
Yeasts
Mutagenesis
Hexoses
Cyclin-Dependent Kinases
Mutant Proteins
Recombinant Proteins
Chemical activation
Phosphates
Scanning

ASJC Scopus subject areas

  • Biochemistry

Cite this

Regulation of glycogen synthase : Identification of residues involved in regulation by the allosteric ligand glucose-6-P and by phosphorylation. / Pederson, Bartholomew A.; Cheng, Christine; Wilson, Wayne A.; Roach, Peter.

In: Journal of Biological Chemistry, Vol. 275, No. 36, 08.09.2000, p. 27753-27761.

Research output: Contribution to journalArticle

@article{729107c2733142cf9966ed9bfc9e0f9a,
title = "Regulation of glycogen synthase: Identification of residues involved in regulation by the allosteric ligand glucose-6-P and by phosphorylation",
abstract = "The major yeast glycogen synthase, Gsy2p, is inactivated by phosphorylation and activated by the allosteric ligand glucose-6-P. From studies of recombinant proteins, the control can be accommodated by a three-state model, in which unphosphorylated enzyme has intermediate activity (state II). Glucose-6-P increased V(max)/K(m) by about 2-fold (state III), whereas phosphorylation by the cyclin-dependent protein kinase Pcl10p/Pho85p decreased V(max)/K(m) by ~30-fold (state I). In the presence of glucose-6-P, state III is achieved regardless of phosphorylation state. The enzyme forms complexes in solution with the yeast glycogenin Glg2p, but this interaction appears not to affect control either by glucose-6-P binding or by phosphorylation. Scanning mutagenesis was applied to identify residues potentially involved in ligand binding. Of 22 mutant enzymes analyzed, seven were essentially inactive. Five mutant proteins were altered in their activation by glucose-6-P, and two were completely unaffected by the hexose phosphate. One of these, R586A/R588A/R591A (all three of the indicated Arg residues mutated to Ala), had wild-type activity and was normally inactivated by phosphorylation. A second mutant, R579A/R580A/R582A, had somewhat reduced V(max), but its activity was not greatly reduced by phosphorylation. The Arg residues in these two mutants are restricted to a highly conserved, 13-residue segment of Gsy2p that we propose to be important for glucose-6-P binding and/or the ability of the enzyme to undergo transitions between activity states.",
author = "Pederson, {Bartholomew A.} and Christine Cheng and Wilson, {Wayne A.} and Peter Roach",
year = "2000",
month = "9",
day = "8",
doi = "10.1074/jbc.M003342200",
language = "English",
volume = "275",
pages = "27753--27761",
journal = "Journal of Biological Chemistry",
issn = "0021-9258",
publisher = "American Society for Biochemistry and Molecular Biology Inc.",
number = "36",

}

TY - JOUR

T1 - Regulation of glycogen synthase

T2 - Identification of residues involved in regulation by the allosteric ligand glucose-6-P and by phosphorylation

AU - Pederson, Bartholomew A.

AU - Cheng, Christine

AU - Wilson, Wayne A.

AU - Roach, Peter

PY - 2000/9/8

Y1 - 2000/9/8

N2 - The major yeast glycogen synthase, Gsy2p, is inactivated by phosphorylation and activated by the allosteric ligand glucose-6-P. From studies of recombinant proteins, the control can be accommodated by a three-state model, in which unphosphorylated enzyme has intermediate activity (state II). Glucose-6-P increased V(max)/K(m) by about 2-fold (state III), whereas phosphorylation by the cyclin-dependent protein kinase Pcl10p/Pho85p decreased V(max)/K(m) by ~30-fold (state I). In the presence of glucose-6-P, state III is achieved regardless of phosphorylation state. The enzyme forms complexes in solution with the yeast glycogenin Glg2p, but this interaction appears not to affect control either by glucose-6-P binding or by phosphorylation. Scanning mutagenesis was applied to identify residues potentially involved in ligand binding. Of 22 mutant enzymes analyzed, seven were essentially inactive. Five mutant proteins were altered in their activation by glucose-6-P, and two were completely unaffected by the hexose phosphate. One of these, R586A/R588A/R591A (all three of the indicated Arg residues mutated to Ala), had wild-type activity and was normally inactivated by phosphorylation. A second mutant, R579A/R580A/R582A, had somewhat reduced V(max), but its activity was not greatly reduced by phosphorylation. The Arg residues in these two mutants are restricted to a highly conserved, 13-residue segment of Gsy2p that we propose to be important for glucose-6-P binding and/or the ability of the enzyme to undergo transitions between activity states.

AB - The major yeast glycogen synthase, Gsy2p, is inactivated by phosphorylation and activated by the allosteric ligand glucose-6-P. From studies of recombinant proteins, the control can be accommodated by a three-state model, in which unphosphorylated enzyme has intermediate activity (state II). Glucose-6-P increased V(max)/K(m) by about 2-fold (state III), whereas phosphorylation by the cyclin-dependent protein kinase Pcl10p/Pho85p decreased V(max)/K(m) by ~30-fold (state I). In the presence of glucose-6-P, state III is achieved regardless of phosphorylation state. The enzyme forms complexes in solution with the yeast glycogenin Glg2p, but this interaction appears not to affect control either by glucose-6-P binding or by phosphorylation. Scanning mutagenesis was applied to identify residues potentially involved in ligand binding. Of 22 mutant enzymes analyzed, seven were essentially inactive. Five mutant proteins were altered in their activation by glucose-6-P, and two were completely unaffected by the hexose phosphate. One of these, R586A/R588A/R591A (all three of the indicated Arg residues mutated to Ala), had wild-type activity and was normally inactivated by phosphorylation. A second mutant, R579A/R580A/R582A, had somewhat reduced V(max), but its activity was not greatly reduced by phosphorylation. The Arg residues in these two mutants are restricted to a highly conserved, 13-residue segment of Gsy2p that we propose to be important for glucose-6-P binding and/or the ability of the enzyme to undergo transitions between activity states.

UR - http://www.scopus.com/inward/record.url?scp=0034623162&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0034623162&partnerID=8YFLogxK

U2 - 10.1074/jbc.M003342200

DO - 10.1074/jbc.M003342200

M3 - Article

VL - 275

SP - 27753

EP - 27761

JO - Journal of Biological Chemistry

JF - Journal of Biological Chemistry

SN - 0021-9258

IS - 36

ER -